Air conditioner



Oct. 28, 1941.

D. E. DASHER AIR CONDITIONER Filed 001'... 28, 1936 2 Sheets-Sheet 1 INVENTOR.

ll/S ATTORNEYS Patented Qct. 28, 1941 AIR CONDITIONER Don E. Dasher, Dayton, Ohio, assignor to General Motors Corporation, Dayton, Ohio, a corporation of Delaware Application October 28, 1936, Serial No. 108,025

2 Claims.

This invention relates to air conditioning systems in which the refrigerating apparatus is used for cooling the air in the summer time and is used for heating the air in the winter time.

An object of this invention is to provide a refrigerating system wherein the refrigerant within the system can be used for both cooling and heating.

A still further object of this invention is to provide a system in which a single heat exchange coil is utilized for both heating and cooling.

A still further object of this invention is to provide an air conditioning system having novel means for controlling the cooling in the summer time and the heating in the winter time.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred form of the present invention is clearly shown.

In the drawings:

Fig. 1 is a view, partly diagrammatic and partly cross-sectional, of an apparatus embodying features of my invention;

Fig. 2 is a diagrammatic View showing the circuit arrangement used with the apparatus shown in Fig. 1;

Fig. 3 is a view, partly diagrammatic and partly cross-sectional, of a modified arrangement of apparatus embodying features of my invention;

Fig. 4 is a diagrammatic view showing the circuit connections used with the apparatus shown in Fig. 3;

Fig. 5 is a diagrammatic view of a slightly diffent' type of control which may be used with the apparatus shown in Figs. 1 and 3.

In this invention, the air conditioning unit may be of the self-contained type, or it may be of the type in which a heat exchange unit is mounted within the room, the air of which is to be conditioned, and the remainder of the apparatusis located in a separate room such as a room in the basement. For purposes of illustrating my invention, I have shown only one heat exchange unit placed in a room; Whereas, in actual practice, a number of units may be mounted in a number of rooms witha central plant for supplying attemporating fluid to the heat exchange units mounted in the various rooms.

In Fig. 1 of the drawings, I have shown a compressor unit H], a motor H for driving the compressor, a heat exchange coil l3 located outside of the enclosure and a complementary heat exchange coil l4 supported in acabinet I5 located within the enclosure It. A by-pass I! is provided between the high side of the compressor unit and the low side, and a three-way valve I8 is inserted at the juncture of the by-pass l1 and the high side line. As shown in the drawings this valve may be set so that fluid circulating between the complementary heat exchange unitsmay flow directly from the one heat exchange unit to the other without passing through the compressor unit. A pipe line l9 connects the heat exchange member M with the usual sump 20. A solenoid valve 2|, a conventional type of restrictor valve 22 and a manuly operated valve 23 are inserted in the line IS. A by-pass 24 having a valve 25 is provided for by-passing fluid around the valves 2|, 22 and 23. A pressure responsive bellows 28 is connected into the line entering the low side of the compressor for operating the switch 29 so as to start and stop the motor in response to the low side pressure in a manner well known in the art. A manual valve 3|) is also placed in the low side line. A coil 3| is in thermal exchange relationship with the coil I3. Steam or hot water is supplied to the coil 3| through the pipe line 33 in which is placed a solenoid valve 34. Steam or hot water leaves the coil via the pipe line 35.

Three-way valves 36 and 31 are placed in the steam line so that when the apparatus is intended to be used for cooling purposes, cold water may be supplied through the pipe line 38 and leave via pipe line 39. A bimetallic thermostat member 40is placed Within the room for controlling the operation of the conditioning apparatus. Contact 4| which is carried by the metallic thermal member 40 engages contact 42 upon the temperature in the room reaching a predetermined high and engages the contact 43 upon the temperature within the room reaching a predetermined low. A fan 45 causes air to flow in through the opening 46 over the heat exchange coil and out through the opening 41 into the space l6.

Whenever it is desired to heat air for the enclosure, manually operated valves 23 and 30 are closed, valve 25 is opened, and the threeway valves I8, 36 and 31 are placed in the position shown in Fig. 1. It is apparent, therefore, that the compressor unit is no longer in fluid flow relationship with the heat exchange units valves set as indicated hereinabove, fluid circulating through the coil it will be heated by steam or hot water flowing through the coil i. The steam, will heat the fluid in the coil l3 and cause the same to rise to the coil id, thereby causing the coil M to become a heater. The gas will condense in the coil l4 and drain back to the sump 20. When no more heating is necessary, the contacts 4! and 63 will separate and cut off the steam supply at valve 34. When it is desired to cool the air for the room, the hand valves 23 and 30 are opened, the valve 25 is closed, the valves 36 and 3! are set so as to supply cold water to the coil 3i, and the three-way valve 58 is set so as to block off the by-pass I I and cause the compressed refrigerant leaving the compressor to flow into the condenser coil Hi. The solenoid valve 2! which is in circuit with contacts 4i and 42 will then control the flow of refrigerant from the sump to the evaporator cooling, it is possible to arrange a plurality ofevaporators in parallel with the liquefying unit.

When a plurality of evaporators are used, a solenoid valve such as 2! will be provided for each evaporator and a single pressure responsive switch 29 will be used in the suction line adjacent the compressor so as to stop the'compressor only at such times when none of the evaporators are in use.

A- manual switch 48 as shown in Fig. 2, is placed in the main circuit so as to completely shut down the fan, the compressor and the control means for the solenoid valves. A second manual switch 49 may be opened if it is desired to operate the fan only. A manually operated switch 50 is also placed in the compressor motor circuit in case it is desired to shut down the compressor during the winter months or during any other desired time. Any conventional furnace may be employed for supplying the steam or hot water to the coil 3|. For that reason, I have not shown any specific furnace. While I have shown manual means for changing over from heating to cooling, it is obvious that automatic means may equally well be employed for this purpose.

the apparatus shown in Figs. 1' and 3, the term "summer" is used to designate any time of -the year when cooling is desired; whereas the term winter is usedto designate those periods when heating is desired. Obviously, during spring and fall especially, frequent changeovers from heating to cooling will take place.

Like reference characters have been used to designate like parts in Figs. 1 to 3.

Except for the arrangement of the fan within the casing 15 and the automatic control means, the apparatus in Fig. 3 is similar to the apparatus in Fig. 1, and for that reason will not be described in detail except for the control means; In the modification shown in Fig. 3, the fan 45 is placed beneath the heat exchange coil ll, so as not-to subject the fan to the hot air passing over the coil l4. Bailles have been provided so as to prevent condensate from dripping on thefan 45.

In Fig. 3 I have shown a furnace which" might equally well be used with the apparatus shown in Fig. l. Burner 56 which is supplied with fuel through line 5! is used for heating the water within the boiler 58. The usual type of thermostatic control means 59 controls the flow of fuel through the valve 60 so as to maintain the proper conditions within the boiler. Reference numeral 6i designates the usual pilot. In order to insure the maintenance of a proper water level within the boiler, float means 62' have been provided for opening the valve 63 in the water supply line 64 upon the water level becoming low and the same float is used for opening the valve 65 so as to permit excess water to drain out through drain 66. While I have shown a single float for maintaining proper liquid level within the boiler, a plurality of floats or any other suitable arrangement may be employed for maintaining the proper liquid level.

Referring now to Fig. 4, reference numeral 10 designates an outside thermostatic means for closing the switch II when the outdoor temperature is sufilciently high to require cooling. Upon the outdoor temperature dropping below a predetermined temperature, the switch 12 will tend to close. Inasmuch as it frequently happens that the outdoor temperature might be high, for example, but the indoor temperature might still be low enough so, that there would be no need for the operation of the cooling apparatus, I have shown a latch means 13 for latching the switch 1| in the open position until the indoor temperature becomes sufficiently high to warrant the operation of the cooling equipment. The latch 13, therefore, is operated by means of a thermostat 16 located within the enclosure. During normal operation, fluctuations in the indoor temperature will not interfere with the switch H so long as the outdoor temperatures are high enough to hold the switch closed.

. Similarly, in order to prevent the operation of the heating equipment before heating is required within the enclosure, I have provided a second latch 15 which latches the switch 12 in the open position until this indoor temperature is .low enough to require heating; The latch 15 is controlled by means of an indoor thermostat 16. The temperatures at which the switches 1| and I2 operate are selected so that only one switch is in the closed circuit position at any given time. In order to be able to render all of the equipment inoperative at will, I have provided. a pair of manual switches 11 and 18 for opening the control circuits. In order to simplify the circuit diagram, each separate solenoid has been shown as operating a separate valve, whereas, in fact, each of the three-way valves is operated by a pair of solenoids. When the manual switch 18 and the automatic switch 'H are both closed, the circuit for the solenoid will be closed with the result that the three-way valve I31 will be set to supply cold water to the coil 3|, and the circuit leading to the solenoid 8| will also be closed with the result that the three-way valve H8 will be set to deliver refrigerant from the compressor to the coil I3. Likewise, the circuit to the solenoid 83 will beclosed so as to set the three-way valve I38 in position for the flow of cooling water, and the circuit leading to the solenoid 84 will be closed so asto' make the valve l2l responsive to the thermal switch 40. The circuit leading to the solenoid 85 will also be closed with the result that the valve I30 will be opened.

Upon the temperature conditions 'outside changing so that heating will be required, and

upon the indoor temperature dropping sufliciently to release the latch I5, the switch I2 will be closed. The closing of switch I2 causes the circuit leading to the solenoid 85 to close, thereby energizing the valve H8 so as to shunt the compressor out of the circuit. The circuit of the solenoid 81 will also be closed with the result that the valve I25 will be opened so that fluid may freely flow from one heat exchanger to the other without passing through the restrictor'valve 2'2 and the solenoid operated valve I2 I. The circuit for the solenoid 88 will, likewise, be closed with the result that the three-way valve I3'I will be shifted so as to permit the fiow of steam through the coil 3|. The circuit for the solenoid 89 will be closed with the result that the three-way valve I36 will be set so as to permit the flow of steam through the coil 3|. Likewise, the circuit will be closed to the solenoid 90 so as to fully open the valve 9| in the fuel supply line. The closing of the switch I2 also energizes the solenoid 92 which opens the valve I34 in the steam'line, provided the circuit is closed between contacts II and 43.

In order to regulate the flow of cooling water when the unit is used for cooling purposes, I have provided the usual'form of valve I which is responsive to the pressure in the line leading from the compressor to the condenser l3. The thermostatic control means 40, which I have described hereinabove, in connection with the apparatus shown in Fig. 1 and also the apparatus shown in Fig. 3, may be replaced by means 'of a slightly modified control apparatus shown in'Fig. 5. The operation of the conditioning unit may bemade responsive to the effective temperature in the enclosure I6. The term effective-temperature is a term now well known in the air conditioning art. An instrument approximating in responsiveness in effective temperature may be used to control the solenoid valves shown. Thus, a relative humidity responsive member II made of wood or the like operates a lever I52 which is connected to a rotatable base I53 upon which is mounted the bimetallic thermostat I54. As the relative humidity changes, the base I53 is slightly rotated about the fulcrum l53a and thus the combination dry-bulb temperature and relative humidity conditions both are effective on a control to close the contacts which govern the operation of the solenoid valves. A suitable rotatable knob I56 may be provided for turning a screw which adjusts the position of the relative humidity responsive member I5I to vary the effectivetemperature at which the instrument opens and closes the contacts.

With applicants arrangement, the apparatus operates like any air conditioning system under summer conditions and in the winter, the valves are all turned to by-pass the compressorand expansion valve and admit steam through the water coil 3|. The steam'passing through the water coil 3| heats the refrigerant in the heat exchange coil- I3 and causes the same to rise to the heat exchange coil l4 with the result that the heat ex- This system, therefore, eliminates the use of a'specialcoil for winter heating.

While the form of embodiment of the present invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

, What is claimed is as follows:

1. In a combination adapted for conditioning air for an enclosure, apparatus for conditioning air for said enclosure comprising a compressor and a plurality of heat exchange units connected in fluid flow relationship, means responsive to the psychrometric condition of the air outside said enclosure for rendering said compressor inoperative, and means for circulating a heating medium in thermal exchange relationship with one of said units while said compressor is inoperative.

2. Air conditioning apparatus for an enclosure comprising a first heat exchange unit, a second heat exchange unit, changeover means for causing either one of said units to reject heat picked up by the other of said units, means responsive 

